Telephone system



May 12, 1936. w. HAi'TON ET AL 2,040,308

TELEPHONE SYSTEM 1 Filed Sept. 15, 1933 2 Sheets-Sheet 2 w HATTON INVENTORSL. B'HAIGH ATTORNEY Patented May 12, 1936 UNITED STATES PATENT OFFICE TELEPHONE SYSTEM ration of New York Application September 13, 1933, Serial No. 689,191 In France September 21, 1932 18 Claims. (01. 179-7.1)

This invention relates to telephone systems and more particularly to measured-service multioflice telephone systems.

The object of the invention is to minimize the apparatus required for timing telephone calls and. secure more eflicient and economical use of such apparatus.

According to the invention, the apparatus required for timing interoflice telephone calls is located in a tandem oflice, the trunking arrangement being such that all such connections are routed through one or more tandem ofiices. As applied to a rural network which includes a number of outlying or satellite ofiices, the timing apparatus is located in the main ofiice.

A feature of the invention relates to satellite systems, arranged for time and zone metering, in which the zone metering apparatus for controlling the operation of a calling subscribers meter is located in the originating office. According to this feature, a conversational circuit in a main ofilce, forming a part of a connection on a call originating in the main oflice or any of its satellite offices, is arranged to transmit metering impulses once only or at the beginning of each unit period of conversation for a call originated by a subscriber of the main office, and to transmit a timing signal over the talking circuit of a connection to the originating ofiice at the beginning of each measured unit period of conversation for a call originated by a subscriber of a satellite ofiice.

A further feature of the invention, relating to satellite systems arranged for time metering in which timing apparatus located in the main exchange is adapted to transmit a signal at the beginning of each measured unit period of conversation, is that the signal consists of the usual release initiating signal, in response to which a connection may be broken down, followed by a cancelling signal before release has been effected.

' Thus, a momentary opening of the talking circuit followed by reclosure may constitute the timing signal, the release of the connection being eflected by an opening maintained until release has occurred.

A further feature relates to satellite systems arranged for time and zone metering wherein calls. to certain zones may be metered a certain number of times for each measured unit period of conversation and may be limited in duration to a definite number of such unit periods, whereas calls to other zones may be metered solely at the beginning of a conversation and be unlimited in duration. According to this feature, a conversational circuit, in a main office and forming a part of a connection on a call originating in the main oflice or any of its satellite oflices,'is arranged to cause operation of the calling subscribers meter once only irrespective of the duration of the call or to cause operation of the meter at every measured unit period of conversation with or without limit of the duration in accordance with the origin of the call and its destination.

The drawings which form a partof this specification disclose in schematic form a system. arranged in accordance with the features of this invention. The inventionis not limited in its application to the particular system shown in the drawings.

7 Referring to the drawings-- Fig. 1 shows a schematic layout of the system which includes a satellite oflice SE and a main ofiice CE;

Fig. 2 shows a subscribers station SI, a link LK comprising the line-finder-SLB anda trunkselector SS, and an outgoing junction circuit OJC, all of which are in a satellite office;

Fig, 3 shows an incoming junction circuit IJC, subscribers stations S2 and S3, a primary linefinder LFI, a link LKI comprising the secondary line-finder LFZ and first selector SSI, a second selector SS2 and a finalselector CS.

The origination of a call by the subscriber at station SI in the satellite ofiice causes this subscribers line to be extended by a link comprising switches SLB and SS to an idle outgoing junction circuit OJC and over the junction J to the incoming junction IJC in the main oflice. Seizure. of the outgoing junction causes a meter control circuit MCC to be operatively associated with the outgoing junction circuit OJC and causes the secondary line-finder LE2 of an idle link LKI in the main oflice to hunt for and connect with the incoming junction IJC. An idle register controller RC is thereupon operatively associated with the link comprising the secondary line-finder LFZ and first selector SSI. When the calling subscriber at station SI dials the number of the subscriber's station with which a connection is desired, the office-code digits are registered in the meter control circuit MCC of the satellite oince and also in the register controller RC of the main oilice. The register controller controls the operation of the first selector SSI and succeeding intermediate and final selectors such as SS2 and CS to complete the connection between the calling station SI in the branch oflice and a called station S2 in the main office, or some other ofiice. Zone metering apparatus in the outgoing junction circuit OJC is selectively positioned under the control of the meter control circuit MCC in accordance with the office code; and zone metering apparatus in the link comprising the line-finder LF2 is selectively positioned in accordance with the ofiice code under the control of the register controller RC. The zone metering apparatus in the link circuit of the main ofilce is arranged to send back a single signal over the junction J at the beginning of each three-minute period during which a talking connection is maintained between the calling and called stations; in response to this signal, the zone metering apparatus of the outgoing junction OJC causes the operation of the calling subscribers service meter once, twice or three times according to the office in which the called station is located. If the calling subscriber does not release the connection by replacing the receiver on the receiver hook before the end of the fourth three-minute period, the connection is automatically opened, a warning tone having been transmitted over the talking connection ten seconds before the end of the twelve minutes.

The origination of a call by the subscriber at station S3 in the main ofiice causes the operation of a primary line-finder such as LFI to hunt for and connect with the calling line; the secondary line-finder LF2 of an idle link such as LKI, is operated to connect with the line-finder LFI and an idle register controller RC is thereupon operatively associated with this link. The calling subscriber dials the called subscribers number and the connection is completed under control of the register controller RC. The zone metering apparatus in the link is selectively positioned in accordance with the ofiice-code registered in the controller RC to operate the calling subscribers service meter as required. If the call is a local call the meter is operated once only and the duration of the call is not limited. On interofiice calls the meter is operated twice or three times at the beginning of each three minute period during which the talking connection is maintained and the connection is automatically broken down at the end of twelve minutes.

The operation of the system shown schematically in Fig. 1 having been described in general, attention will now be given to this system as disclosed in Figures 2 and 3. Referring to Fig. 2, the subscribers station SI is connected by a line Ill to terminals in the bank of the finder switch SLB in a branch ofiice. The selector switch SS is permanently connected to the line finder SLB; together the line-finder and the selector form the link circuit LK. The subscribers station equipment is of the usual type employed in automatic telephone systems and includes a dial or impulse sending device for use in establishing connection with any other station as desired. The line circuit apparatus individual to line H1 in the branch office is represented by the service meter 15. These line and link circuits may be similar to those shown in Fig. 1 of the patent to W. Hatton et al. No. 1,831,387 granted November 10, 1931, and reference may be had to this patent for a description of the operation of these circuit units.

The outgoing junction circuit OJC, which is one of a group of such circuits to which the selector SS has access, is substantially the same as that shown in Fig. 2 and described in the specification of the aforementioned Patent No. 1,831,387 exceptthat there is no clock circuit and timing switch available in the branch office for controlling the advance of themetering switch. All

apparatus included in the circuit unit OJC other than that required for a clear and complete description of this invention has been omitted. This circuit as shown includes an incoming supervisory relay 2|, an outgoing supervisory relay 22, and a release relay 24. Associated with the outgoing junction circuit is a metering switch SMS comprising the stepping magnet 39 and three brushes 3|, 32 and 33 with their associated banks of terminals, the zone relays 34 and 35, and the control relays 36 and 31. The meter control circuit MCC which receives and records the ofice-code digits of the number dialed by the calling subscriber is similar to that shown in Fig. 3, and described in the specification, of the aforementioned Patent No. 1,831,387.

The junction J, to which the outgoing junction circuit OJC is connected, terminates at the main office in the incoming junction circuit IJ C shown in Fig. 3. The line conductors of the incoming junction circuit are connected to terminals in the bank of the line-finder LFZ which together with the first selector SSI forms a main ofiice link circuit LKI similar to that shown in Fig. 15, and described in the specification, of the aforementioned Patent No. 1,831,387. The main office subscribers station S3 and associated line circuit which is represented by the service meter 55 are also the same as the station and line circuits shown in Fig. 15, and described in the specification, of said patent, The primary line-finder LFI which is represented by a set of brushes and the one set of terminals may be similar to that disclosed in the patent to E. P. G. Wright No. 1,901,940 granted March 21, 1933. The register controller RC, which receives and records the ofiice-code digits of the number dialed by the calling subscriber at the same time that they are received and registered in the branch office meter control circuit MCC, is the same as that shown in Figs. 9 and 10, and described in the specification, of the aforementioned Patent No. 1,831,387. The intermediate group and final selectors, SS2 and CS, each represented schematically by a set of brushes and one set of terminals, are similar to the group selector shown in Fig. 14 and the final selector shown in Figs. 12 and 13, and both described in the specification, of the aforementioned Patent No. 1,831,387.

A call having been originated by the subscriber at station SI in the branch ofiice, the line I9 is extended by the line-finder SLB and the selector SS to an idle outgoing junction circuit OJC. Upon seizure of OJC, the operation of relay 2! causes the meter control circuit MCC to be operatively associated with the junction circuit and also causes the main office end of the junction J to be extended by the line-finder LF2 of an idle link circuit to the associated selector SSI, all as described in the aforementioned Patent 1,831,387. The finding of junction line J by the finder LFZ causes the operation of relays 43 and 44 of the incoming junction circuit IJC and also causes the operative association of the register controller RC with the link LKI as described in the aforementioned Patent 1,831,387. When the number of the called station is dialed, the response of relay 2| is effective to repeat the dial impulses to the meter control circuit MCC and also over the junction J to relay H of the main office link circuit; and relay H repeats the impulses to the associated register-controller RC. The operation of the first selector SS! is thereafter controlled by the register-controller RC to make the required group selection. Intermediate and final selectors 1 circuit for operating relay 15.

such as SS2 and CS are operated under control of the register-controller BC to complete the connection to the called line which is designated I98; selectors SS2 and CS and line 100 may be in the same office, as that in which the link LKI is located, or in another office. Relays 2|, 22, and 24 of the outgoing junction circuit OJC, relays 43 and 44 of the incoming junction circuit IJC, and relays 65, 66, 61 and H of the link'circuit LKI are all operated. Relays 34 and 35 of the outgoing junction circuit OJC are each operated or normal depending upon the zone within which the called station is located as indicated by the ofiice-code registered in the meter control circuit MCC. Relays 1-6 and 11 of the main oflice link circuit LK! are also each operated or normal depending upon the zone within which the called station is located as indicated by the office-code registered in the register-controller RC. For a complete description of the operation of'th'e various circuit units involved in completing a connection, reference may be had to the aforementioned Patent No. 1,831,387.

If the call originates at station S3 in the .main

, office, the calling line is extended by the operation of the primary line-finder LFI and the secondary line-finder LFZ to the link LKI, a register-controller RC is operatively associated with the link, and the connection through an intermediate group selector and a final selector to the called line in the same or another oifice.

When the receiver is removed at the called station, supervisory relay 14 operates and. closes a Relay T5 locks under control of relay 6'! and if either of the zone indicating relays T6 or T1 is operated, relay 18 is operated due to the energization of its left winding. Relay 18 closes a locking circuit through its left winding under control of relay l5 and closes a circuit for operating the start relay 85 of the timing switch TS. If neither of relays l6 or 1'! is operated but the call is one originating in the branch office, relay [8 is operated as hereinafter described. The operation of relay also closes a circuit for advancing the metering switch SM out of normal position; this circuit is traced from battery through the winding of stepping magnet 90, through the brush and normal contact of'bank 9|, the middle right front contact of relay 15, through interrupter 94 to ground. After the switch SM is moved out of normal position, the magnet 94 is operated each time the interrupter closes the connection to ground thereby advancing the switch step-bystep to the last off-normal position.

Assuming the cal1 to have originated in the branch office, the advance of switch SM to its first off-normal position closes a circuit 'from ground through the right winding of relay 18,

first off-normal terminal and brush 92 of switch SM, to brush 64 of line-finder LF2 and through the terminal with which brush 64 is in contact, to cause the momentary operation of relay 45 of the incoming junction circuit IJC and the operaton of relay l8. Relay '18 looks and closes the circuit for operating the start relay 85 of timing switch TS. In oil-normal positions 3, 1 and 8, and 9 to H inclusive, connections are closed from battery 95 through the contacts of zone relays l6 and 1'! dependent upon whether these relays are operated or normal, to brush 64 of line-finder LF2; but these connections are inefiective to cause the operation of relay 45. The aforemenis completed tioned. operation of start relay 85 closes a circuit from thestepping'magnet 80 of timing switch TS to the clock circuit '86 whereby the switch TS is advanced to immediately open the connection between the springs of cam 84 and hold it open for aperiod of. twelve minutes. At cam 8 l, a connection is temporarily closed through its springs 3 minutes, '6 minutes, and 9 minutes after the switch is advanced out of normal position, thereby causing the switch SM to return to normal and then repeat its cycle of operations 3 minutes, 6 minutes, and 9 minutes after'its first cycle. .At the end of 11 minutes and 50 seconds after the switch TS begins to advance, the cam 83 closes a connection from ground through the right winding of tone source 19, inner right front contact of relay 15, through the springs of cam 83 to condenser 12, a tone being thereby transmitted to the calling subscriber to indicate that the connection is about to be broken down. Cam 82 closes a connection through its springs l2 minutes after the switch TS begins to advance, thereby short-circuiting and causing the release of relay 65. The release of relay 65 causes the release of relays 61 and 15, thereby breaking down the connection by causing the return of the line-finder LF2 to normal.

The operation of relay 45 at the beginning of each cycle of the advance of switch SM causes a temporary opening of the lower talking conductor of junction J, ground being connected through the front contact of relay 45 to prevent the release of relay H due to this temporary operation of relay 45. The temporary opening of the lower conductor of junction J at the beginning of each three minute period of conversation,

after the called subscriber answers, causes a corresponding temporary release of the supervisory relay 22 of the outgoing junction circuit OJC. The release of relay 22 causes the release of relay 24 and closes a circuit for operating relay 36. Relay 36 locks through its inner left front contact through the normal terminal and brush of bank 32 to ground; all off-normal terminals of this bank. except the last are strapped to the normal terminal so as ,to hold relay 36 until switch SMS reaches the last of its off-normal positions. As soon as relay 22 reoperates (due to the release of relay 45), 1'elay 24 reonerates and a circuit is closed for operating relay 3]. Since the release of relays 22 and 24 is temporary the connection is maintained even though this metering signal is similar to the release signal. Relay 31 looks under control of relay 3%? and con nects interrupter 38 to the winding of the s reaches its last off-normal position. During the time that relay 24 is released, a circuit is closed through the winding of thermostatic relay 25 which requires a thirty second energization to cause its operation and the consequent release of the link LK. The circuit for operating the calling subscribers service meter I5 is closed during the advance of switch SMS by the nonbridging brush of bank 33 either once, twice, or three times, dependent upon the operated or normal condition of the zone relays 34 and 35. Thus with relays 34 and 35both operated, the operating circuit for service meter I5 is closed in each of positions I0, I I and I2 of the switch SMS; with relay 35- operated and relay 34 normal the operating circuit Ior meter I5 is closed in each of positions 8 and 9; and with neither of relays 3a or 35 operated, which condition exists on a call between subscribers both located in the branch oificek, the meter operating circuit is closed only in position 5. When the switch SMS reaches the last oiT-norma1 position, relays 36 and 31 are released and magnet 30 reoperates to ground at its own back contact to advance the brushes 3|, 32 and 33 to normal position. The operation of switch SMS is repeated at the end of 3 minutes, 6 minutes and 9 minutes of conversation due to the temporary release of relay 22 as controlled by the above described operation of switches SM and TS in the main oiiice.

When the calling subscriber releases the connection, relay 2| releases thus opening the supervisory loop over junction J whereby relay 22 of the outgoing junction circuit OJC and relay ll of the main omce link circuit LKl are released. The release of relay H causes the release of relay 6? and the return of the link LKI to normal. The release of relay 22 causes the release of relay 2A and the continued energization of the winding of thermostatic relay 25. The operation of relay 25 at the end of 33 seconds causes the release of the link LK and return of switches SLE and SS to normal.

'On calls originating from station S3 in the main ofiice, the advance of switch SM closes the operating circuit for service meter 55 in each of positions 5, Hi and II if zone relays 16 and 11 are both operated, in each of positions I and 8 if relay 11 only is operated, and in position 3 if neither of relays 16 nor TI is operated. If the called station is in the same ofiice with station S3, the switch SM does not repeat its cycle of operations since none of relays 16, TI and 13 are operated and the start relay of the timing switch TS is not operated; the conversation may therefore continue, without interruption for 12 minutes, and metering occurs only at the beginning of the conversation.

In the system shown in Figs. 2 and 3, it is seen that the timing switch TS and controlling clock mechanism 86 at the main exchange are employed in timing all calls, except local calls, originated in both the branch and main ofiices, there being no timing apparatus or clock mechanism in the branch ofiice.

What is claimed is:

1. In a measured-service telephone system, subscribers lines, a branch ofiice, a main ofiice, a conversational circuit unit in said main office for use in completing calls originating in said main since and for completing calls originating in said branch office, means for extending a connection from a calling line in said branch oiiice to said conversational circuit unit, and timing means in said conversational circuit unit for transmitting a timing signal over the talking connection to said branch office at the beginning of each measured unit period of time during which a talking connection is maintained on a call originating in said branch office.

2. In a measured-service telephone system, subscribers lines, a branch ofiice, a main office, means for extending a connection from a calling line in said branch ofiice to said main ofiice, apparatus in said main oflice for counting off unit periods of time during Which a talking connection is maintained on calls originating in, terminating at, or routed through said main ofiice, and means controlled by said apparatus for transmitting a timing signal to said branch oifice at the beginning of each of such unit periods on calls originating in said branch oflice and for charging the calling subscriber for each of such unit periods on calls originating in said main office.

3. In a measured-service telephone system, subscribers lines, a branch oiiice, a main ofiice, means for extending a connection from a calling line in said branch oflice to said main ofiice, apparatus in said main oflice for counting off unit periods of time during which a talking connection is maintained on calls originating in, terminating at, or routed through said main office, means in said main ofiice for transmitting a release signal on calls originating at said branch oifice to cause release of the connection, and means controlled by said apparatus for transmitting a timing signal at the beginning of each of such unit periods, said timing signal comprising said release signal followed by a canceling signal prior to release of the connection.

4. In a measured-service telephone system, subscribers lines, individual message registers for said lines, a branch ofiice, a main office, a conversational circuit unit in said main ofiice for use in completing calls originating in said main office and for use in completing calls originating in said branch office, means for extending a connection from a calling line in said branch office to said unit, means for extending a connection from a calling line in said main ofiice to said unit, means in said unit for counting oii unit periods of time during which a talking connection is maintained on calls originating in either of said ofiices, and means in said unit eiiective on a call originating in said main ofiice to cause the operation of the calling subscribers message register upon establishment of a talking connection without repeating said charging operation thereafter during the continued maintenance of the connection.

5. In a measured-service telephone system, subscribers lines, individual message registers for said lines, a branch ofiice, a main oifice, a conversational circuit unit in said main office for use in completing calls originating in said main office and for use in completing calls originating in said branch oflice, means for extending a connection from a calling line in said branch ofiice to said unit, means for extending a connection from a calling line in said main oiiice to said unit, means in said unit for counting oiT unit periods of time during which a talking connection is maintained on calls originating in either of said ofiices, and means in said unit effective on a call originating in said main ofiice to cause the operation of the calling subscribers message register upon establishment of a talking connection and for thereafter repeating said charging operation at the beginning of each succeeding period or part thereof.

6. In a measured-service telephone system, subscribers lines, individual message registers for said lines, a branch ofiice, a main ofiice, a conversational circuit unit in said main office for use in completing calls originating in said main office and for use in completing calls originating in said branch office, means for extending a connection from a calling line in said branch ofiice to said unit, means for extending a connection from a calling line in said main ofiice to said unit, means in said unit for counting off unit periods of time during which a talking connection is maintained on calls originating in either of said ofiices, means in said unit for causing the operation of a calling subscribers register upon establishment of a desired talking connection without repeating said charging operation during the continued maintenance of the connection, and means. in said unit for causing the operation of a calling subscribers register upon establishment of a desired talking connection and for causing said charging operation to be repeated at the beginning of each succeeding unit period or part thereof.

'7. In a measured-service telephone system, subscribers lines, individual message registers for said lines, a branch oflice, a main otfice, a conversational circuit unit in said main oflice for use in completing calls originating in said. main ofiice and for use in completing calls originating in said branch ofiice, means for extendinga connection from a calling line in said branch oifice to said unit, means for extending a connection from a calling line in said main oifice to said unit, means in said unit for counting of]? unit periods of time during which a talking connection is maintained on calls originating in either of said offices, means in said unit for causing the operation of a calling subscribers register upon establishment of a desired talking connection without repeating said charging operation during the continued maintenance of the connection,v means in said unit for causing the operation of a calling subscribers register upon establishment of a desired talking connection i and for causing said charging operation to be repeated at the beginning of each succeeding unit period or part there.- of, and means in said unit for terminating a talking connection at the end of a predetermined number of said periods.

8. In a measured-service telephone system, subscribers lines, individual message registers for said lines, a branch ofiice, a main oifice, a conversational circuit unit in said main office for use in completing calls originating in said main ofiice and for use in completing calls originating in saidbranch ofiice, means for extending a connection from a calling line in said branch office to said unit, means for extending a connection from a calling line in said main office to said unit, means in said unit for counting ofi unit periods of time during which a talking connection is maintained on calls originating in either of said ofiices, means in said unit for causing the operation of a calling subscribers register upon establishment of a desired talking connection without repeating said charging operation during the continued maintenance of the connection, means in said unit for causing the operation of a calling subscribers register upon establishment of a desired talking connection and for causing said charging operation to be repeated at the beginning of each succeeding unit period or part thereof, means in said unit for terminating a talking connection at the end oi a predetermined number of said periods,

and means for transmitting a signal to a calling subscriber a short interval prior to the termination of said predetermined number of periods.

9. In a measured-service telephone system, a

" plurality of offices, subscribers lines, service meters one for each of said lines, means in each of said ofiices for operating the service meter of a calling line, means in each of said ofiices for use in completing calls originating or terminating in the ofiice in which said means is located, other means in one of said oifices for use in completing calls originating in another office and terminating in another office, timing apparatus in said one of the ofiices for counting off predetermined periods of time, and means responsive to the answer of the called subscriber on any of said calls and controlled by said timing. apparatus tor causing the operation of the meter operating meansin the office in which a call originates.

10. In a telephone system, a first ofiice, a second oirlce, a third ofiice, subscribers lines, service meters one for each of said lines, means including a trunk extending from said first ofiice to said second. ofiice for use in completing calls originating in said first office and terminating in either of said other ofiices, means associated with said trunk in said first office for operating the service meter of a calling line, a link in said second office for use in completing calls incoming over said trunk and for use in completing calls originating in said second ofiice, timing means in said second ofiice for measuring off unit periods oftime while a talking connection is maintained through said link, and means in said link for use in transmitting a timing signal over said trunk to said meter operating means in the first office. at the. beginning of each of said measured unit periods of time on calls incoming over said; trunk to said link, each of said timing signals being effective to set in operation said meter operating means in said first ofiice.

11. In a telephone system, a first ofiice, a second oifice, a third ofiice, subscribers lines, service meters one for each of said lines, means including a trunk extending from said first oflice to said second oifice for use in completing calls originating in said first office and terminating in either of said other oiiices, means associated with said trunk in said first ofiice for operating the service meter of a calling line, a link in said second office for use in completing calls incoming over said trunk and for use in completing calls originating in said second ofiice, timing means in said second ofiice for measuring ofi unit periods of time while a talking connection is maintained through said link, and means in said link for use in transmitting a timing signal over said trunk to said meter operating means in the first oifice at the beginning of each of said measured unit periods of time on calls incoming over said trunk to said link and for use in operating the service meter of a calling line on calls originating in said second ofiice.

12. In a multi-ofiice telephone system, subscribers lines, service meters one for each of saidlines, an impulse dial at each subscribers station for use in establishing a desired connection,

means including a trunk extending from a first ofiice to a second ofiice for use in completing calls originating in said first office and terminating in another office, means in said first office and associated with said trunk for registering in response to digits dialed by a calling subscriber the zone destination of the call, timing means in said second office for counting off unit periods of time while a talking connection is maintained over said trunk and for'transmitting a signal at the beginning of each of said periods over said trunk, and charging means in said first oilice set in operation upon receipt of each of said timing signals for operating the calling subscribers meter one or more times, the number of meter operations being controlled by said zone registering means.

13. In a telephone system, a branch office, a main ofiice, measured-service subscribers lines in each of said offices, individual meters for said lines, other subscribers lines, a trunk for use in extending a call from a calling line in said branch office to said main oifice, means in said branch oifice associated with said trunk for use in operating the meter of a calling line in the branch ofiice, a link in said main ofiice for use in completing calls originating in said main oifice and for use in completing calls incoming to said main oflice over said trunk, means associated with said link for counting off unit periods of time during which a talking connection is maintained on calls originating in either of said offices, and means in said link efiective on a call originating in said branch oflice for transmitting at the beginning of each of said unit periods of time a signal to cause the operation of said meter operating means in the branch ofiice.

14. In a telephone system, a branch office, a main office, measured-service subscribers lines in each of said ofilces, individual meters for said lines, other subscribers lines, a trunk for use in extending a call from a calling line in said branch office to said main office, means in said branch ofiice associated with said trunk for use in operating the meter of a calling line in the branch office, a link in said m'ain office for use in completing calls originating in said main office and calls incoming to said main ofiice over said trunk, means associated with said link for use in operating the meter of a calling subscriber in said main office, timing mechanism associated with said link for measuring off unit periods of time while a talking connection is established through said link, and means effective on a call originating in said branch office and comprising the meter operating means associated with said link and said timing mechanism for transmitting to said branch ofiice a signal over said trunk to render effective said meter operating means in said branch office.

15. In a measured-service telephone system, subscribers lines, individual message registers for said lines, a branch oflice, a main oifice, a conversational circuit unit in said main ofiice for use in completing calls originating in said main office and for use in completing calls originating in said branch office means for extending a connection from a calling line in said branch office to said unit, means for extending a connection from a calling line in said main oflice to said unit, means in said unit for counting ofi unit periods of time during which a talking connection is maintained on calls originating in either of said offices, means in said unit operatively responsive to the answer of the called subscriber for causing the operation of the calling subscribers register, and means effective during the continuance of the talking connection on calls other than calls local to said main ofiice for causing said operation of the calling subscribers register to be repeated at the beginning of each succeeding measured period of time.

16. In a measured-service telephone system, subscribers lines, individual message registers for said lines, a branch oflice, a main office, a conversational circuit unit in said main office for use in completing calls originating in said main ofiice and for use in completing calls originating in said branch office, means for extending a connection from a calling line in said branch office to said unit, means for extending a connection from a calling line in said main office to said unit, means in said unit for counting off unit periods of time during which a talking connection is maintained on calls originating in either of said ofiices, means in said unit and operatively effective on calls local to said main ofiice for causing the operation of the calling subscribers register upon establishment of a desired talking connection without repeating said charging operation during the continued maintenance of the connection, and means in said unit and operatively effective on all calls except calls local to said main ofiice for causing the operation of the calling subscribers register upon estabishment of a desired talking connection and for causing said charging operation to be repeated at the beginning of each succeeding unit period or part thereof.

17. In a measured-service telephone system according to claim 16, means in said conversational circuit unit for terminating a talking connection at the end of a predetermined number of said measured unit periods of time.

18. In a measured-service telephone system according to claim 16, means in said conversational circuit unit for terminating a talking connection at the end of a predetermined number of said measured unitperiods of time, and means for transmitting a signal to a calling subscriber a short interval prior to the termination of said predetermined number of measured-periods of time.

WILLIAM HATTON. LESLIE B. HAIGH. 

